The U.S. government is making sure you can't quietly cruise through the neighborhood in a hybrid anymore.

Future hybrids and EVs might not be nearly as stealthy in the United States because the National Highway Traffic Safety Administration could soon require that they make an audible alert at speeds below 19 miles per hour (30 kilometres per hour). NHTSA estimates the rule could prevent 2,400 pedestrian injuries a year.

"This is a common-sense tool to help pedestrians — especially folks who are blind or have low vision — make their way safely," NHTSA Administrator Dr. Mark Rosekind said when announcing the new regulation.

According to the new rule, electrified vehicles would produce a minimum tone of 47 to 50 decibels with the power on when stationary. In reverse, the sound would increase to 50 to 53 decibels. When driving forward up to six mph (10 km/h), the volume would grow to 53-56 decibels. Then the noise would increase to 59 to 62 decibels at 12 mph (20 km/h) and 63 to 67 decibels at 19 mph (30 km/h). For reference, a normal conversation is between 50 and 60 decibels.

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NHTSA estimates a cumulative cost to the auto industry of $39 million USD a year for installing waterproof external speakers for creating these sounds, according to Reuters. However, the parts could mean $250 million to $320 million USD a year in lower medical costs from fewer people being hit by the cars.

The Alliance of Automobile Manufacturers lobbying group worked with NHTSA on creating the rules. The group seems cautiously optimistic about the results. “We’re still reviewing this final rule, however we already know that it’s important that automakers have the flexibility to equip vehicles with sounds that are sufficiently detectable yet pleasant to hear. Consumer acceptance is critical and that hinges on sounds not annoying people inside the auto,” it said in a statement.

If accepted, at least half of all new hybrids and EVs for sale in the U.S must have this equipment by September 1, 2018, and all of them would require it by September 1, 2019. Motorcycles and heavy-duty vehicles with a gross weight rating of 10,000 pounds (4,536 kilograms) or more would be exempt from this regulation.

Groups that support blind people praised the new rule for improving the safety for those with poor sight. “This regulation will ensure that blind Americans can continue to travel safely and independently as we work, learn, shop, and engage in all facets of community life," Mark A. Riccobono, President of the National Federation of the Blind, said during NHTSA’s announcement.

NHTSA has been hammering out this regulation since Congress passed The Pedestrian Safety Enhancement Act of 2010. However, the rules aren’t quite final yet. According to Reuters, Donald Trump’s administration could order an additional review of the regulation once it takes power.

New requirement of audible alert will help prevent 2,400 pedestrian injuries a year

WASHINGTON – The U.S. Department of Transportation's National Highway Traffic Safety Administration (NHTSA) today announced that it is adding a sound requirement for all newly manufactured hybrid and electric light-duty vehicles to help protect pedestrians. The new federal safety standard will help pedestrians who are blind, have low vision, and other pedestrians detect the presence, direction and location of these vehicles when they are traveling at low speeds, which will help prevent about 2,400 pedestrian injuries each year once all hybrids in the fleet are properly equipped.

"We all depend on our senses to alert us to possible danger," said U.S. Transportation Secretary Anthony Foxx. "With more, quieter hybrid and electrical cars on the road, the ability for all pedestrians to hear as well as see the cars becomes an important factor of reducing the risk of possible crashes and improving safety."

Under the new rule, all hybrid and electric light vehicles with four wheels and a gross vehicle weight rating of 10,000 pounds or less will be required to make audible noise when traveling in reverse or forward at speeds up to 30 kilometers per hour (about 19 miles per hour). At higher speeds, the sound alert is not required because other factors, such as tire and wind noise, provide adequate audible warning to pedestrians.

"This is a common-sense tool to help pedestrians — especially folks who are blind or have low vision — make their way safely," said NHTSA Administrator Dr. Mark Rosekind. "With pedestrian fatalities on the rise, it is vitally important we take every action to protect the most vulnerable road users."

Manufacturers have until Sept. 1, 2019, to equip all new hybrid and electric vehicles with sounds that meet the new federal safety standard. Half of new hybrid and electric vehicles must be in compliance one year before the final deadline.

"We commend NHTSA on bringing this process to completion," said Eric Bridges, executive director of the American council of the Blind. "This new safety standard moving forward will not just make our streets safer for blind and visually impaired Americans, but also serve as an additional safety cue for all pedestrians who share the streets with hybrid or electric vehicles."

"Having raised concerns on behalf of blind Americans about the dangers posed by silent hybrid and electric vehicles, the National Federation of the Blind is extremely pleased that technical specifications for a safe level of sound to be emitted by such vehicles have now been issued," said Mark A. Riccobono, President of the National Federation of the Blind. "The full implementation of the Pedestrian Safety Enhancement Act of 2010 will protect all pedestrians, especially the blind, as well as cyclists. This regulation will ensure that blind Americans can continue to travel safely and independently as we work, learn, shop, and engage in all facets of community life.

ALLIANCE STATEMENT ON EV MINIMUM SOUND STANDARDNovember 14, 2016

The Alliance worked closely with the National Federation of the Blind to support the Congressional legislation that directed NHTSA to develop this standard.

We’re still reviewing this final rule, however we already know that it’s important that automakers have the flexibility to equip vehicles with sounds that are sufficiently detectable yet pleasant to hear; consumer acceptance is critical and that hinges on sounds not annoying people inside the auto. Additionally, just as current conventionally-powered vehicles sound differently than one another, it’s critical that the noise requirements for their electrically powered counterparts are not so rigid they require a single sound signature.

The Alliance continues working with the NFB, and other stakeholders on the development of a Global Technical Regulation (GTR) for sound for hybrid and electric vehicles in accordance to the United Nations Working Party (WP) 29 “98 Agreement”.